Solve: $\dfrac{3}{2} - \dfrac{5}{6} - \dfrac{2}{9} = $
Solution: Let's look at the multiples of each denominator and see which multiples they have in common. Denominator Multiples ${2}$ $2, 4, 6, 8, 10, 12, 14, 16, \underline{{18}}$ ${6}$ $6, 12, \underline{{18}}, 24$ ${9}$ $9, \underline{{18}}, 27$ The least common multiple is ${18}$. Let's use multiplication to make each fraction have a denominator of $18$. $\begin{aligned} &{\dfrac{3}{2}}=\dfrac{{3} \times 9}{{2} \times9} = {\dfrac{27}{18}}\\\\ &{\dfrac{5}{6}}=\dfrac{{5} \times 3}{{6} \times3} = {\dfrac{15}{18}}\\\\ &{\dfrac{2}{9}}=\dfrac{{2} \times 2}{{9} \times2} = {\dfrac{4}{18}} \end{aligned}$ $\begin{aligned} &{\dfrac{3}{2}} - {\dfrac{5}{6}} - {\dfrac{2}{9}}\\\\ =& {\dfrac{27}{18}} - {\dfrac{15}{18}} - {\dfrac{4}{18}}\\\\ =&\dfrac{{27} - {15} - {4}}{18}\\\\ =&\dfrac{12 - 4}{18}\\\\ =&\dfrac{8}{18} \end{aligned}$ ${\dfrac{3}{2}} - {\dfrac{5}{6}} - {\dfrac{2}{9}} = \dfrac{8}{18}$ $ \dfrac{8}{18}$ can also be written as $\dfrac{4}{9}$.